1. Field of the Disclosure
The present disclosure relates to an image capturing lens system, and more particularly, to a compact image capturing lens system used in electronic products.
2. Description of the Related Art
The demand for compact imaging lens assembly has grown in recent years as the popularity of portable electronic products with the photographing function has increased. The sensor of a general photographing camera is none other than CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor) sensor. Furthermore, as the advanced semiconductor manufacturing technology has allowed the pixel size of sensors to be reduced, and the current electronic products are leaning toward a trend of being more compact, there is an increasing demand for higher image quality.
A conventional compact imaging lens system with high image quality equipped on a portable electronic product is often composed of four lens elements such as the lens system set forth in U.S. Pat. No. 8,179,470. However, with the popularity of high level portable electronic products, such as smart phone and PDA (Personal Digital Assistant), the demand for the pixel size and image quality of compact imaging lens system increase fast, and the conventional lens system with four lens elements can no longer satisfy the imaging lens systems of even higher level.
Recently, lens systems adopting five lens elements begin to emerge, such as the lens system set forth in U.S. Pat. No. 8,000,030. However, the object side surfaces of both of the second lens element and the third lens element fail to obtain enough curvature; therefore, the capability of astigmatism correction is limited and the resolution thereof is affected. Furthermore, since the lens system struggles in handling the off-axis incident-light, it tends to have a vignetting effect in the formed image and the relative illumination of the lens system is so low that the image quality becomes undesirable.
In light of the foregoing, an image capturing lens system that is suitable for portable electronic devices and has excellent image quality is in need; especially for those whose second lens element and third lens element have particularly balanced curvature, which is favorable for astigmatism correction for improving resolution and moderating the angle of incidence from the off-axis field for increasing relative illumination.